UK supermajor BP and its partners now expect project approval for the first of three long-awaited floater projects in Angola later this year.
Until recently, the partners in Block 31 had been hoping for the go-ahead from state oil company Sonangol in the second quarter.
However, Marathon Oil was not specific, talking only about sometime this year.
Contracting sources privately said they would be surprised if anything of importance happened before the end of the year.
It is unclear what the hold-up is although sources outline a number of possibilities such as continuing local content deliberations plus parliamentary elections planned for September this year, followed by a presidential run-off in 2009.
Contractors SBM Offshore and Modec are doing battle to win conversion contracts for up to four floating production, storage and offloading vessels three on Block 31 and another one on Block 18.
In what numbers these FPSO orders will be placed is unclear, but what is certain is that the first vessel will be dedicated to the Block 31 North East project, also known as PSMV after the Plutao, Saturno, Marte and Venus discoveries it will exploit.
The PSMV floater, designed to produce about 150,000 barrels per day of crude, is due on stream in 2012 and could eventually handle production from the Terra oil discovery to the west, according to a Marathon presentation.
Marathon said the other two Block 31 projects are in feasibility mode although the vessels required there are thought to be similar to the PSMV unit, so little further engineering work would have to be done and they could potentially be fast-tracked.
Block 31 Mid is focused on the Titania, Ceres, Hebe, Cordelia, Portia and Miranda finds while Block 31 South East will likely exploit the Astraea, Urano, Juno and Palas discoveries.
Block 18 West is the remaining floater scheme based around the Chumbo field and a decision on its development looks to have been put back to 2011 at the earliest.
Marathon's exploration boss Phil Behrman told investors that BP and Total planned to drill between five and six exploration and appraisal wells on blocks 31 and 32 respectively this year.
However, with attention now switching to development activities on both blocks, drilling will be pared back with Behrman predicting two to four wells going down in total in 2009 and up to two the following year.
Total is believed to be studying an FPSO-based scheme on Block 32, based either solely on its Gengibre discovery or a joint development of Gengibre with Canela and Gindungo.